The simple answer is: because we are not good at it. But that begs the question –why aren’t we? Are we inherently incapable of not grasping mathematical concepts? Well, here is a surprising answer: some of us really are, about 3 -6% of us. There is even a name for this deficiency: dyscalculia, meaning math disability. Its manifestations can range from the fundamental inability to conceptualize numbers as abstract concepts of comparative quantities (2 is larger than 1), to difficulty in everyday tasks such as confusing the + and – signs, difficulty in the multiplication table, difficulty in addition and subtraction, difficulty in balancing a checkbook, etc. Some dyscalculics have difficulty in distinguishing between left and right, or estimating time (“how long does it take cross the street?”). Interestingly, many excel in writing, and many authors and journalists (especially those writing about finance, I assume) suffer from the dyscalculia syndrome. The deficiency in its severest form suggests that it must be due to some neuro –anatomical defect. Indeed, acquired dyscalculia due to some traumatic event is part of Gerstmann syndrome, a lesion in the border area between the parietal and temporal lobes (the angular gyrus, for the detail oriented).
But this is not a lesson in Neurology, and 95% of us don’t suffer from this deficiency. I am mentioning it as evidence that mathematical computation is an inherent ability that we all possess. Infants can estimate the number of objects (up to three) almost from birth, and this capacity is increasing rapidly with age so that within months the number of estimated objects increases to 5. Why should such ability be hard-wired? Because it has a survival value. Whether a single lion is approaching, or a pride of 3, can make a great difference in how you handle the situation. If computation is so basic to survival, wouldn’t you think that other animals should have this capacity as well? Indeed chimpanzees have been shown to be able to estimate the number of predators from infancy. But we don’t have to go that far in evolutionary time. Who hasn’t estimated the length of a line before choosing one? It sounds elementary, but I find it fascinating that such mundane, taken-for –granted actions are grounded in ancient evolutionary principles.
Computation is not the only inherent mathematical ability. Dr. Veronique Izard studied children in the U.S, France, and the Munduruku tribe in the Amazon forest. She showed that understanding geometric concepts can be demonstrated at very early ages. For instance, the concept that two parallel lines will never cross is present by age 7. Intuitively understanding that the shortest distance between two points is a straight line is present even earlier. Again, we take this ability for granted precisely because it is hard-wired in the brain.
What are the implications?
We are woefully deficient in our ability to think quantitatively. Our brain is not programmed to ponder and analyze “simple” decisions whether to fight or run for our lives. But in our complex world this is no more the type of decisions we have to make. We have to weigh the costs and benefits of keeping the air clean, of fighting wars of choice, of providing liver transplants vs. immunizations. These are quantitative decisions and we do have the neurological matrix for making them. The reason why Singapore, Hong-Kong, and Finland score the highest in mathematical achievement, and we are average and below is not due to innate differences –it is due to differences cultural attitudes. In the countries with mathematical excellence teachers are viewed as professionals. In Singapore a math teacher receives constant training, five hour a week, and earns as much as an engineer in public service. In Finland only top college graduates are admitted to education school, and they earn high salaries that are commensurate with the public esteem in which they are held. In our country, a teacher earns less than a prison guard, and frequently has to buy school supplies for the children out of her own pocket. The cost/benefit analysis is quite clear. What is not clear is whether we can muster the will to get our priorities right.